Power transformer units condition assessment using virtual instrumentation

Knowledge of the short-circuit impedance variation is necessary for verifying the observance of the technical conditions (including the design conditions), certain nonconformities in the winding execution, checking the winding behavior in operation, verifying the system and short-circuit calculation (including the correct protection setup), the loading of the same type units, or more importantly, of the different type ones. The measurement of the short-circuit impedance by means of a three phase low voltage power source can be performed because the value of impedances does not depend on the applied voltage. ICEMENERG has developed a modem measurement system that has been used for performing a great amount of measurements, the results of which have been compared with those of the manufacturer's, and with those obtained by means of high voltage measurements. Ill. 3, bibl. 8 (in English; summaries in English, Russian and Lithuanian).